7 comments:

That's how I feel about most of what I learned inside the classroom throughout all of high school. On the other hand, the things I learned outside the classroom during school, say, in the halls, backseats of cars, etc, turned out to be incredibly useful stuff. :)

From AskNSDL.org (https://ask.nsdl.org/default.aspx?id=14530&cat=1167)

Pi is pretty pervasive. Probably the most common use is to figure out areas of such things a cylinders and spheres. For example, to know how much paint you need to cover a barrel. Or how much rubber you need to make a ball. Maybe even how big a round pan you need to bake a cake that you usually make in a square pan. But pi can be found in many other areas. Pi turns up all over the place in probability. For example, if you get a bunch of toothpicks and draw a bunch of parallel lines on the ground spaced by the length of a toothpick, and then drop the toothpicks randomly on the ground, the proportion of toothpicks touching a line is 2/pi, about .637. Perhaps you don't think this counts as everyday life, but these days a lot of computer transactions are encrypted. Some of the algorithms involved in encryption deal with numbers which are "relatively prime", which means they don't share any factors besides 1. It turns out that if you pick two numbers at random, the probability that they are relatively prime is 6/pi^2, which is about .608. Pi often turns up in physics equations, too, but you probably wouldn't think of that as everyday life.